The present invention relates to a conveyor roller bearing housing. More particularly, the conveyor roller bearing housing of the present invention is intended to minimize relative movement between the bearing housing and the roller tube.
A polyurethane end cap assembly for the roller tube of conveyor rollers is described in Australian Patent 686028 to the present applicant. The end cap assembly is described as comprising a solid end cap body which is interference fitted within an end of a roller tube and in which is received a bearing. The bearing is fitted within the end cap body from an inner side of the end cap body, thereby minimizing the exposure of the bearing to dust and dirt from outside the conveyor roller. A removable inner seal means is snap fitted within the end cap body behind the bearing and acts to seal the bearing from any dust and dirt within the conveyor roller. The outer face of the bearing is sealed by an inner collar portion of the end cap body which projects inwardly towards the roller shaft and on which are provided a pair of arms. One of these arms engages an inner race of the bearing whilst the other engages the shaft. Further, a dust seal is press fitted to the roller shaft externally to the end cap body and projections provided thereon engage lightly an outer surface of the end cap body allowing free rotation of one relative to the other, but providing an initial barrier to the ingress of dust and dirt to the end cap assembly.
Whilst the end cap assembly described in Australian Patent 686028 operates well in dampening noise and vibration in conveyor rollers, it consumes a large volume of polyurethane which manifests as high production costs.
A conveyor roller having a socket adapted to hold the bearing within the roller tube is described in SU 1671566. Further, the socket is shown to comprise recesses (5) and (9) provided in the inner and outer faces thereof, these recesses projecting into the socket and encroaching between the bearing and the roller tube. A conveyor roller with end covers provided between the bearing and the roller tube is described in EP 0799777. The end cover is the equivalent of the socket of SU 1671566 and similarly has recesses provided in the inner and outer faces thereof, at least one of these recesses encroaching between the bearing and the roller tube.
WO 97/47541 describes therein a conveyor roller comprising in part a shaft, about which a bearing is provided, the bearing being held within adaptors. The adaptors have protrusions projecting radially therefrom to engage the inner surface of the roller tube and facilitate the mechanical connection therebetween. The protrusions are arranged in a lateral manner relative to the length of the roller and shaft, and not in a longitudinal manner. The protrusions are not located directly between the bearing and the roller tube, but are rather spaced apart therefrom.
The above constructions of SU 1671566, EP 0799777, and WO 97/47541, if the end cap/end cover/socket were to be made, at least in part, of a deformable or at least partly flexibly resilient material such as polyurethane, would be subject to slippage and consequently increased wear and vibration. During use, a polymeric material such as polyurethane is subject to stress relaxation, this having a detrimental effect on the fit of the end cap within the roller housing. This may lead to damage and/or destruction of the end cap during continued use.
The conveyor roller shaft bearing housing of the present invention has as one object thereof to substantially overcome the above problems associated with the prior art, or to at least provide a useful alternative thereto.
The preceding discussion of the background art is intended to facilitate an understanding of the present invention only. It should be appreciated that the discussion is not an acknowledgement or admission that any of the material referred to was part of the common general knowledge in Australia as at the priority date of the application.
Throughout this specification, unless the context requires otherwise, the word xe2x80x9ccomprisexe2x80x9d, or variations such as xe2x80x9ccomprisesxe2x80x9d or xe2x80x9ccomprisingxe2x80x9d, will be understood to imply the inclusion of a stated integer or group of integers but not the exclusion of any other integer or group of integers.
In accordance with the present invention there is provided a conveyor roller bearing housing characterised by comprising a body portion proportioned to receive and locate in a bearing seat therein at least one bearing, and to be disposed between at least one of the or each bearing and a roller tube, the body portion further having an outer surface arranged in large part to engage the roller tube, wherein the body portion has provided therein at least one recess in the outer surface to reduce the volume of material in the body portion, whereby there is at all times a load bearing column in the body portion between the bearing seat and the outer surface to substantially minimise any stress relaxation therein.
Preferably, the or each recess provided in the outer surface is located intermediate forward and rear faces provided on the body portion.
Still preferably, a plurality of recesses are provided in the outer surface extending radially into the body portion at regular intervals thereabout.
In one form of the present invention the body portion is formed of a flexibly resilient material. Preferably, the body portion is formed of polyurethane.
In another form of the present invention the or each radial recess has an insert provided therein. The insert may be formed of a stronger or harder material than that from which the body portion is formed.
Preferably, any recesses provided in the forward or rear faces of the body portion do not encroach upon the area thereof located radially between at least one of the or each bearings and the roller tube.